The government says the system, which merges six existing benefits into one, offers extra support and that budgeting and financial help was available.

Mr Gauke is expected to make a decision in the coming days about whether the roll-out should be accelerated.

‘Work should pay’

But Dame Louise, who has advised four prime ministers on social policy over the past 18 years, including Mrs May, said it had to be paused to get “the implementation completely right”.

“I completely agree that we all should be wedded to the principle, and therefore the overall policy, that work should pay,” she told PM.

But she added: “If it means that we are looking at more and more people that are ending up homeless, or ending up having their kids taken away, or ending up in more dire circumstances, that cannot be the intention.

“It can’t be and it won’t be the intention of Theresa May or [first secretary of state] Damian Green or any of those people. I just don’t believe that they would want that to happen.”

She suggested ministers were blindly “pressing on” with the policy because they did not want to be accused of doing a U-turn. But she said: “It’s like jumping over a cliff – once you have jumped, people end up at the bottom and we don’t want that to happen.”

‘Poll tax’

Figures published by the Department for Work and Pensions show that around one in four new Universal Credit claimants waited longer than six weeks to be paid.

That could make a big difference to families who were “close to the edge,” Dame Louise said. They “will end up in dire circumstances, more dire than I think we have seen in this country for years”.

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The BBC understands Tory MPs, led by Heidi Allen, have written to minister David Gauke to demand a pause to the national roll-out of Universal Credit, which Labour claims could become Theresa May’s “poll tax”.

Homeless ‘because of Universal Credit’

Garry Dunningham, 24, lives in a tent by the river in Great Yarmouth.

He says he and his girlfriend were evicted from their shared flat about six months ago once their landlord found out they were on Universal Credit.

“Basically because we were on Universal Credit and he’s had a lot of people not paying the rent… we got kicked out.”

Garry says he has tried 58 private landlords across the town but no one will take them.

“As soon as I go to meet them and say I am on Universal Credit, it’s a no: ‘We ain’t got no rooms.'”

He says being homeless has impacted his chances of finding work: “You need an address. It’s a vicious circle.”

He has even offered to pay rent and a deposit in advance “but they won’t even do that”.

“No one’s giving us the benefit of the doubt. You can’t always judge everyone by what other people have done but that’s what they’re doing.

“I’ve walked down the street and there’s been house after house empty… and no one will let us in.”

Shadow work and pensions secretary Debbie Abrahams welcomed the support of Conservative MPs for a pause, saying it could be used to bring in advance payments, rather than loans, for struggling families and to scrap charges on the helpline number, among other things.

Conservative MP Stephen McPartland said his concern with Universal Credit was that for “every pound these people earn, extra, the government’s taking 63p back off them”.

“To me that is an effective tax rate of 63%, which is ridiculous. So the lowest paid are effectively having to pay some of the highest taxes,” he told the World at One.

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A spokesman for the department of work and pensions said Universal Credit was “working” and people were “moving into work faster and staying in work longer than under the old system”.

“The vast majority of claimants are paid in full and on time, and are comfortable managing their money. Advance payments and budgeting support is available for anyone who needs extra help.”

Dame Louise first came to prominence as Tony Blair’s “anti-social behaviour tsar” and also led a programme for David Cameron to tackle “troubled families”. She has now left the government to work for an international homelessness charity.

She told the BBC she was concerned that a report she published last year on integration had been placed in a box marked “too difficult”.

Prevent strategy

The government has yet to issue a formal response to the review, which accuses public bodies of ignoring or condoning divisive or harmful religious practices for fear of being called racist.

It also suggests immigrants could take “an oath of integration with British values and society” and calls for more money for English lessons.

Dame Louise also suggested in her BBC interview that ministers had undermined their own anti-extremism strategy, Prevent, by not defending it strongly enough when it was attacked by critics.

She said Prevent needed “a big revamp” but added “we have not been robust enough – the government was not robust enough – in both its defence of it and its delivery”.